Fluid pump system

ABSTRACT

A fluid pump system for a fluid delivery system is disclosed. The fluid pump system includes a drive cylinder and a drive piston slidably disposed in the drive cylinder. A drive rod including a crowned end is connected to the drive piston. The fluid system further includes a pump cylinder and a pump piston slidably disposed in the pump cylinder. A pump rod including a crowned end is connected to the pump piston. The drive rod and the pump rod are configured to be detachably coupled to each other, wherein the crowned end of the drive rod cooperates with the crowned end of the pump rod.

TECHNICAL FIELD

The present disclosure relates to a fluid pump system, and more particularly to the fluid pump system having a drive cylinder and a pump cylinder.

BACKGROUND

A fluid pump system for cryogenic applications includes a pump cylinder and a drive cylinder adapted to power the pump cylinder. A single rod connects a drive piston of the drive cylinder and a pump piston of the pump cylinder. A pressurized fluid received from a fluid source pushes the drive piston connected with the rod which further drives the pump piston of the pump cylinder. The pump piston further pressurizes and pumps a cryogenic fluid to a storage or usage site.

For example, PCT Published Application No. WO9711273A1 relates to a pumping system for transferring fluid from a source to a storage or usage point against a head pressure and without the need for a power source at the fluid source. The pumping system includes a reciprocating drive means controlled by a valve means connected to a pressure supply. The drive means drives a driven means in fluid communication with a fluid source and adapted to pump the fluid source to a storage or usage site. The ratio of volumes of drive to driven means is adjustable to enable efficient use of the pump at different supply pressures and for different volume or pressure output requirements.

SUMMARY

In one aspect, the present disclosure provides a fluid pump system for a fluid delivery system. The fluid pump system includes a drive cylinder and a drive piston connected with a drive rod slidably disposed in the drive cylinder. A drive rod is connected to the drive piston includes a crowned end. The fluid system further includes a pump cylinder and a pump piston slidably disposed in the pump cylinder. A pump rod is connected to the pump piston and includes a crowned end. The drive rod and the pump rod are configured to be detachably coupled to each other, wherein the crowned end of the drive rod cooperates with the crowned end of the pump rod.

In another aspect, the present disclosure provides a fluid delivery system. The fluid delivery system includes a tank for storing a fluid. A fluid pump system is configured to pressurize the fluid received from the tank. The fluid pump system includes a drive cylinder and a drive piston connected with a drive rod slidably disposed in the drive cylinder. A drive rod is connected to the drive piston includes a crowned end. The fluid system further includes a pump cylinder and a pump piston slidably disposed in the pump cylinder. A pump rod is connected to the pump piston and includes a crowned end. The drive rod and the pump rod are configured to be detachably coupled to each other, wherein the crowned end of the drive rod cooperates with the crowned end of the pump rod.

In another aspect, the present disclosure provides a load transfer arrangement for a fluid pump system. The load transfer arrangement includes a drive rod, a pump rod and each of the drive rod and the pump rod include a crowned end of a convex outer surface having a predetermined radius. A connector is configured to detachably couple the drive rod and the pump rod and the crowned end of the drive rod is adjacent to the crowned end of the pump rod. Further, a distal portion of at least one of the drive rod and the pump rod includes a recess configured to cooperate with a tongue of the connector.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic of a fluid delivery system, according to an aspect of the present disclosure;

FIG. 2 illustrates a cross-sectional view of a drive cylinder and a pump cylinder of a fluid pump system; and

FIG. 3 illustrates a perspective view of a load transfer arrangement of the fluid pump system.

DETAILED DESCRIPTION

Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, corresponding or similar reference numbers will be used, when possible, to refer to the same or corresponding parts.

FIG. 1 illustrates a schematic of a fluid delivery system 100, according to an aspect of the present disclosure. The fluid delivery system 100 includes a reservoir 102 to store a fluid, such as, but not limited to, a cryogenic fluid and a fluid pump system 104 configured to pressurize the fluid stored in the reservoir 102. The fluid pump system 104 is configured to supply the pressurized fluid to an accumulator 106 or other storage or supply devices for use thereof. The fluid pump system 104 includes a drive cylinder 108 and a drive piston 110 slidably disposed in the drive cylinder 108. Further, drive rod 112 is connected to the drive piston 110. The drive piston 110 may define a first chamber 114 and a second chamber 116 in the drive cylinder 108. Further, the fluid pump system 104 includes a pump cylinder 118 and a pump piston 120 slidably disposed in the pump cylinder 118. Further, a pump rod 122 is connected to the pump piston 120. The pump piston 120 may further define a first chamber 124 and a second chamber 126 in the pump cylinder 118.

In an exemplary embodiment of the present disclosure, a pump 130 may supply hydraulic fluid to the drive cylinder 108. In alternative embodiments, the drive cylinder 108 may be driven by any alternative sources, but not limited to, pneumatically driven pumps. The pump 130 may be a variable displacement pump of any well-known construction and type, such as, a gear pump, a rotary vane pump, a screw pump, an axial piston pump or a radial piston pump. The pump 130 is configured to pressurize a fluid received from a tank 132 and supply the pressurized fluid to the drive cylinder 108 via a control valve 134. In an aspect of the present disclosure, the control valve 134 may be a directional control valve to start, stop or change the flow of the pressurized fluid from the tank 132 to the drive cylinder 108. The control valve 134 may be a solenoid operated valve which selectively controls a flow of pressurized fluid from the pump 130 into an inlet port 136 provided in the first chamber 124 of the drive cylinder 108 and from an outlet port 138 provided in the second chamber 126 of the drive cylinder 108 to the tank 132. Moreover, a controller (not shown) may be configured to output a signal to the control valve 134 to control the flow of the fluid back and forth the pump 130 to the drive cylinder 108.

In an exemplary embodiment of the present disclosure, the fluid received from the reservoir 102 is received into a port 140 provided in the first chamber 124 of the pump cylinder 118 via a first check valve 142. The first check valve 142 is configured to allow the fluid in a single direction as indicated from the reservoir 102 to the pump cylinder 118 via a fluid line 144. The pressurized fluid received from the control valve 134 is configured to push the drive piston 110 connected with the drive rod 112. The drive rod 112 is further configured to push the pump rod 122 connected with the pump piston 120. The movement of the pump rod 122 is configured to pressurize the fluid received from the reservoir 102 in the first chamber 124 of the pump cylinder 118. Further, the pressurized fluid may be configured to flow into an accumulator 106 via a second check valve 146. The second check valve 146 is configured to allow the pressurized fluid in a single direction as indicated from the pump cylinder 118 to the accumulator 106 via the fluid line 144. In an aspect of the present disclosure, the drive rod 112 and the pump rod 122 are configured to be detachably coupled to each other by a connector 128, which is further explained in FIGS. 2 and 3.

FIG. 2 illustrates a cross-sectional view of the drive cylinder 108 and the pump cylinder 118 of the fluid pump system 104 of FIG. 1. The drive cylinder 108 may include a first end 148 closed by a head cap 150 and a second end 152 may be adapted to receive an end cap 154. The end cap 154 provided on the drive cylinder 108 may be sealingly engaged with an inner wall 156 of the drive cylinder 108. In an embodiment, the inner wall 156 of the drive cylinder 108 may include threads for engagement with complementary threads provided on the end cap 154. Moreover, a seal groove 158 may also be provided along an outer surface 160 of the end cap 154, and a seal 162 may be provided therein for ensuring a sealing engagement between the end cap 154 and the inner wall 156 of the drive cylinder 108. In an aspect of the present disclosure, a groove 164 may be provided on an internal wall 172 of the end cap 154. Further, a bearing 174 may be seated in the groove 164. The bearing 174 may be of any type of rod end bearings, such as, but not limited to, spherical rod bearings. The bearings 174 may be made of material, such as, but not limited to, brass, bronze, iron, or steel and often plated with zinc or chromium. Additionally, grooves 166, 168, 170 may be provided along the internal wall 172 of the end cap 154 for seating a buffer seal 176, a rod seal 178, and a wiper seal 180, respectively. The configuration explained above for the drive cylinder 108 is similar and applicable to the pump cylinder 118.

In an aspect of the present disclosure, the end caps 154 of the drive cylinder 108 and the pump cylinder 118 may include an opening 182 therein, such as a longitudinal through bore, to slidably receive the drive rod 112 and the pump rod 122, respectively. The fluid pump system 104 may further include a load transfer arrangement 184. The load transfer arrangement 184 includes the drive rod 112 and the pump rod 122, and each of the drive rod 112 and the pump rod 122 are provided with a first crowned end 186 and a second crowned end 187. Further, the crowned ends 186, 187 may be provided at distal ends of the drive rod 112 and the pump rod 122. The crowned ends 186, 187 may include a convex or spherical shape having a predetermined radius. Although the crowned ends 186, 187 is shown as a convex shape in the present disclosure, a person ordinarily skilled in the art may understand that the distal ends of the drive rod 112 and the pump rod 122 may have alternate shapes, such as, but not limited to, semispherical or hemispherical. In an aspect of the present disclosure, the crowned ends 186, 187 of the pump rod 122 and the drive rod 112 are disposed adjacent to each other. Further, the crowned ends 186, 187 are configured to provide a clearance for mild translational or angular misalignment of the drive rod 112 and the pump rod 122.

In an aspect of the present disclosure, a distal portion 188 of each of the drive rod 112 and the pump rod 122 may include a recess 190. The recess 190 provided on the distal portion 188 of the drive rod 112 and the pump rod 122 may be configured to receive the connector 128. In an aspect of the present disclosure, the connector 128 may be a cylindrical connector. As shown in FIG. 3, the connector 128 is a split connector and is configured with a generally “C” shaped cross section. Further, the connector 128 may include a pair of axially spaced tongues 192 extending inward. The tongues 192 of the connector 128 is further configured to cooperate with the recess 190 provided on the distal portion 188 of the drive rod 112 and the pump rod 122. The tongues 192 received in the recess 190 are configured to detachably couple the pump rod 122 with the drive rod 112. Although the connector 128 is shown as a single connecting member in the present disclosure, those skilled in the art may understand that one or more connectors with multiple projections or tongues and may be made of thin spring metal or from a plastic material without deviating from the scope of the present disclosure.

In an aspect of the present disclosure, the load transfer arrangement 184 may further include a sleeve 194 configured to attach the drive cylinder 108 with the pump cylinder 118. The sleeve 194 may include a tubular member of a first half sleeve and a second half sleeve. Flanges 196 may be provided on ends of the sleeve 194 and may be configured to be fastened to the end cap 154 of at least one of the drive cylinder 108 and the pump cylinder 118. The flange 196 may be fastened to the end cap 154 of the drive cylinder 108 and the pump cylinder 118 by a mechanical fastener 200, such as, but not limited to, bolting. As illustrated in FIG. 3, the sleeve 194 may include a guide 198 centrally disposed about the drive cylinder 108 and the pump cylinder 118 along an axis. The guide 198 provided on the sleeve 194 is configured to provide a path for a translational motion of the connector 128.

INDUSTRIAL APPLICABILITY

The industrial applicability of the fluid pump system for a fluid delivery system described herein will be readily appreciated from the foregoing discussion. Typically, a fluid pump system consists of a pump cylinder which is hydraulically powered by a drive cylinder. Further, the drive cylinder including a drive piston and the pump cylinder including a pump piston are connected by a single rod. The usage of single rod may result in stressing of sealing members. In an aspect of the present disclosure, the fluid pump system 104 uses separate rods including the drive rod 112 connected with the drive piston 110 and the pump rod 122 connected with the pump piston 120. The drive rod 112 and the pump rod 122 may be assembled separately and further can be detachably coupled by the connector 128. Further, the fluid pump system 104 may be applicable to various pump configurations, such as not, but not limited to, LNG pumps.

As illustrated in FIGS. 2 and 3, during a pushing movement of the drive rod 112 on the pump rod 122, the crowned ends 186, 187 of the drive rod 112 and the pump rod 122 cooperate with each other providing a clearance for mild translational or angular misalignment. Further, the bearings 174 provided on the end caps 154 of the drive cylinder 108 and the pump cylinder 118 may absorb the load during translation or angular misalignment of the drive rod 112 and the pump rod 122. These load absorption of the bearings 174 may reduce stress on the buffer seal 176, the rod seal 178, and the wiper seal 180 or other sealing elements provided along the inner wall 172 of the end caps 154 of the drive cylinder 108 and the pump cylinder 118 and may provide improved seal operating environments through tighter clearances. Further, during a pulling movement of the drive piston 110 on the pump rod 122, the connector 128 may be in the loaded condition and the tongues 192 provided on the recess 190 of the drive rod 112 and the pump rod 122 may hold the drive rod 112 and the pump rod 122 together.

In an aspect of the present disclosure, the flange 196 attaching the drive cylinder 108 and pump cylinder 118 may allow the pulling and pushing movements of the drive rod 112 and the push rod 122 along an axis X-X′. Further, the flange 196 defines the guide 198, as shown in FIG. 3 which may allow the translation motion of the connector 128.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method of assembling fuel pump on the engine without departing from the scope of the disclosure. Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications or variations may be made without deviating from the spirit or scope of inventive features claimed herein. Other embodiments will be apparent to those skilled in the art from consideration of the specification and figures and practice of the arrangements disclosed herein. It is intended that the specification and disclosed examples be considered as exemplary only, with a true inventive scope and spirit being indicated by the following claims and their equivalents. 

What is claimed is:
 1. A fluid pump system for a fluid delivery system comprising: a drive cylinder and a drive piston slidably disposed in the drive cylinder, a drive rod including a crowned end is connected to the drive cylinder; a pump cylinder and a pump piston slidably disposed in the pump cylinder, the pump rod including a crowned end is connected to the pump cylinder; and the drive rod and the pump rod configured to be detachably coupled to each other, wherein the crowned end of the drive rod cooperates with the crowned end of the pump rod.
 2. The fluid pump system of claim 1, wherein a connector is configured to detachably couple the drive rod and the pump rod.
 3. The fluid pump system of claim 1, wherein each of the crowned ends includes a convex outer surface having a predetermined radius.
 4. The fluid pump system of claim 1, wherein a distal portion of at least one of the drive rod and the pump rod includes a recess.
 5. The fluid pump system of claim 4, wherein the recess provided on the distal portion of at least one of the drive rod and the pump rod is configured to cooperate with a tongue of the connector.
 6. The fluid pump system of claim 1, wherein a sleeve is configured to attach the drive cylinder with the pump cylinder, the sleeve including a guide disposed about the drive cylinder and the pump cylinder.
 7. The fluid pump system of claim 6, wherein the sleeve includes a flange configured to be fastened to an end cap of at least one of the drive cylinder and the pump cylinder.
 8. The fluid pump system of claim 6, wherein the sleeve defines the guide configured to provide a path for translational motion of the connector.
 9. A fluid delivery system comprising: a tank for storing a fluid; a fluid pump system configured to pressurize the fluid received from the tank, the fluid pump system comprising: a drive cylinder and a drive piston slidably disposed in the drive cylinder, a drive rod including a crowned end is connected to the drive cylinder; a pump cylinder and a pump piston slidably disposed in the pump cylinder, the pump rod including a crowned end is connected to the pump cylinder; and the drive rod and the pump rod configured to be detachably coupled to each other, wherein the crowned end of the drive rod cooperates with the crowned end of the pump rod.
 10. The fluid delivery system of claim 9, wherein a connector is configured to detachably couple the drive rod and the pump rod.
 11. The fluid delivery system of claim 9, wherein each of the crowned ends includes a convex outer surface having a predetermined radius.
 12. The fluid delivery system of claim 9, wherein a distal portion of at least one of the drive rod and the pump rod includes a recess.
 13. The fluid delivery system of claim 12, wherein the recess provided on the distal portion of at least one of the drive rod and the pump rod is configured to cooperate with a tongue of the connector.
 14. The fluid delivery system of claim 9, wherein a sleeve is configured to attach the drive cylinder and the pump cylinder, the sleeve including a guide disposed about the drive cylinder and the pump cylinder.
 15. The fluid delivery system of claim 14, wherein the sleeve is configured to be fastened to an end cap of at least one of the drive cylinder and the pump cylinder.
 16. The fluid delivery system of claim 14, wherein the sleeve defines the guide configured to provide a path for translational motion of the connector.
 17. A load transfer arrangement for a fluid pump system comprising: a drive rod having a crowned end; a pump rod having a crowned end; and a connector configured to detachably couple the drive rod and the pump rod, wherein the crowned end of the drive rod is adjacent to the crowned end of the pump rod.
 18. The load transfer arrangement of claim 17, wherein each of the crowned ends includes a convex outer surface having a predetermined radius.
 19. The load transfer arrangement of claim 17, wherein a distal portion of at least one of the drive rod and the pump rod includes a recess.
 20. The load transfer arrangement of claim 19, wherein the recess provided on the distal portion of at least one of the drive rod and the pump rod is configured to cooperate with a tongue of the connector. 